Speaker
Описание
In this talk I will present our very recent work based on [1].
We introduce novel relations between the derivatives ($\partial^{n}{\rho(\lambda,m_l)}/{\partial m_l^{n}}$) of the
Dirac eigenvalue spectrum ($\rho(\lambda,m_l)$) with respect to the light sea quark mass ($m_l$)
and the $(n+1)$-point correlations among the eigenvalues ($\lambda$) of the massless
Dirac operator. Using these relations we present lattice QCD results for
$\partial^{n}{\rho(\lambda,m_l)}/{\partial m_l^{n}}$ ($n=1, 2, 3$) for $m_l$ corresponding to pion masses
$m_\pi=160-55$ MeV, and at a temperature of about 1.6 times the chiral phase
transition temperature. Calculations were carried out using (2+1)-flavors of highly
improved staggered quarks with the physical value of strange quark mass, three
lattice spacings $a=0.12, 0.08, 0.06$ fm, and lattices having aspect ratios $4-9$.
We find that $\rho(\lambda\to0,m_l)$ develops a peaked structure. This peaked
structure arises due to non-Poisson correlations within the infrared part of the
Dirac eigenvalue spectrum, becomes sharper as $a\to0$, and its amplitude is
proportional to $m_l^2$. We demonstrate that this $\rho(\lambda\to0,m_l)$ is
responsible for the manifestations of axial anomaly in 2-point correlation
functions of light scalar and pseudo-scalar mesons. After continuum and chiral
extrapolations we find that axial anomaly remains manifested in 2-point correlation
functions of scalar and pseudo-scalar mesons in the chiral limit.
[1] H.-T. Ding, S.-T. Li, Swagato Mukherjee, A. Tomiya, X.-D. Wang, Y. Zhang, arXiv:2010.14836.
